Descriptive Flex Fields (DFF) Context Segment Default Type Parameter
I was looking at the different options available when configuring DFFs, in particular different contexts segments, which change the DFF's available depending on the context selected. For example, if you wanted to have different DFFs depending on different scenarios, for example depending on the Ledger. This is possible using the Manage General Ledger Descriptive Flex Fields screens.
Looking at the implementation guide, it describes a scenario as follows;
Your company has multiple ledgers. When entering journal lines for the Vision Corporation ledger, users must enter a source voucher number as additional information. For the Spruce Street Foods ledger, users must enter both a source voucher number and a source voucher date. The remaining ledgers don't have to track this information.